This invention relates generally to system for powering a compacting machine and, more particularly, to a system for electrically powering and vibrating a compacting machine roller in a variable manner.
Asphalt has an extensive history in the development of the construction industry and is widely utilized for a number of applications in our public and commercial infrastructure. The technology and composition of various asphalt combinations have been developed over the years such that various asphalt combinations can be mixed in a manner to be specially tailored to a specific application. They can be mixed with various sizes, distributions, and shapes of aggregate, as well as different types of aggregate such as gravel, old tires, coal fly ash, and many others. Each combination or mixture of asphalt can also be applied at different temperatures. Typically, the asphalt mixture is transported to the work site, poured in loose form, leveled and then compacted to provide a relatively hard, smooth surface. Thus, each asphalt mixture exhibits its own characteristics and the optimum compaction of each mixture is dependent on those characteristics. Incorrect compaction, either too much or too little, can induce cracking of the asphalt and therefore premature breakdown of the paved surface.
Compacting machines in various forms are well known in the art. Especially well known are self-propelled mobile compacting machines used for compacting soil, rock and asphalt for roadways, construction, and the like. Present compacting machines generally comprise a heavily weighted frame or chassis supported by one or more rollers to assist in provided compacting force. A gas or diesel engine is indirectly coupled with at least one of the rollers to power the compacting machine in a forward or reverse direction so that the machine can make multiple passes over the material in order to properly compact it into a hard surface for supporting vehicles and the like.
Compacting machines often include a hydraulic motor that rotates a shaft or mechanism having an off-center or eccentric weight at a predetermined speed to provide a vibrational component to the roller in addition to the weight of the machine thereby assisting in the compaction. Such hydraulic motors utilize operating fluids, which may spill or leak onto the asphalt or ground.
Most of these vibration-inducing mechanisms operate at a frequency and amplitude that are preset at manufacture, or the mechanism may only have a minimal number of alternate adjustments and are not readily variable. Thus, there is a need in the industry for a compacting machine that can be vibration adjusted to provide an optimum compaction for different materials while minimizing the danger of contaminating the environment.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.
In one aspect of this invention, a system is provided for variably powering and vibrating a compaction roller on a compacting machine for use in compacting surfaces. The system includes a chassis and at least one compaction roller rotatably journaled to the chassis. The compaction roller forms the rotor of a variable reluctance motor for driving the roller in a rotational manner and for vibrating the roller.
In another aspect of the invention, a compacting machine is provided for compacting surfaces. The compacting machine includes a chassis and at least one compaction roller rotatably journaled to the chassis for compacting the surface. At least one electric motor is also included wherein a first portion of the motor is affixed to the chassis and a second portion of the motor is affixed to the compaction roller for direct electrical drive of the compaction roller.